Thirty-five years ago this week in South Korea, protesters in the city of Gwangju staged a violent uprising against the country’s then military government, an act credited with starting the country’s democratic revolution.

At the time, demonstrators were angry after troops fired on a student demonstration, killing and beating students. They seized weapons from armories and police stations, setting up an even bigger confrontation.

Jeong Eee-haeng was caught up in the fight between protestors and the South Korean military. “I remember I was on my way to work on May 18, 1980 when soldiers were parachuted into the city," he said. "They started chasing me.”

The May 18 Memorial Foundation said at least 154 people were killed when soldiers retook the city from demonstrators who opposed South Korea’s military dictatorship.

Dozens more went missing and around 4,000 civilians were injured during the fighting that ended 9 days later.

At the time, Seoul labeled the uprising as pro-communist.

George Katsiaficas, author of Asia’s Unknown Uprisings, said that is one reason why some foreign powers, like the United States, did not condemn the crackdown.

“They were very much worried that a democracy in Korea, in South Korea, would mean a regime hostile to the United States,” he said.

Katsiaficas added that without the Gwangju uprising, South Korea would not be a democracy today.

But, he and other observers said they are worried about how the country is handling more recent protests.

In April, South Korean riot police forcibly put down a demonstration led by the families of those who died on the Sewol ferry, raising protests from groups supporting free speech such as Amnesty International.

Some participants of the Gwangju uprising, like Na Il-sung, said this and other recent incidents make their sacrifice seem in vain.

“It has been 35-years since our protest and we have made progress, South Korea is a democracy. But I feel some of this progress is now rolling back and it worries me as a survivor,” he said.